[Bug rtl-optimization/41862] New: valgrind warns about using uninitialized variable with -fgcse-sm

[zsojka at seznam dot cz]

4.5.0 r153685 

Command line:
$ valgrind --track-origins=yes -v
/mnt/svn/gcc-trunk/binary-153685-lto/libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/cc1
-fpreprocessed testcase.i -m32 -O1 -version -fgcse-sm -o tmp.o

...

GNU C (GCC) version 4.5.0 20091028 (experimental) (x86_64-unknown-linux-gnu)    
        compiled by GNU C version 4.5.0 20091028 (experimental), GMP version
4.3.1, MPFR version 2.4.1-p5, MPC version 0.7 

...

==5211== 43 errors in context 1 of 2:                                           
==5211== Conditional jump or move depends on uninitialised value(s)             
==5211==    at 0x7B2215: store_killed_after (store-motion.c:270)                
==5211==    by 0x7B3221: execute_rtl_store_motion (store-motion.c:1084)         
==5211==    by 0x71349C: execute_one_pass (passes.c:1519)                       
==5211==    by 0x7136C4: execute_pass_list (passes.c:1568)                      
==5211==    by 0x7136D6: execute_pass_list (passes.c:1569)                      
==5211==    by 0x80B8B0: tree_rest_of_compilation (tree-optimize.c:392)         
==5211==    by 0x9836AB: cgraph_expand_function (cgraphunit.c:1160)             
==5211==    by 0x985524: cgraph_optimize (cgraphunit.c:1219)                    
==5211==    by 0x985A5E: cgraph_finalize_compilation_unit (cgraphunit.c:1089)   
==5211==    by 0x4AE2DA: c_write_global_declarations (c-decl.c:9489)            
==5211==    by 0x7B8CAB: toplev_main (toplev.c:1061)                            
==5211==    by 0x6587A25: (below main) (in /lib64/libc-2.10.1.so)               
==5211==  Uninitialised value was created by a heap allocation                  
==5211==    at 0x4C270AC: malloc (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)                          
==5211==    by 0xC90C27: xmalloc (xmalloc.c:147)                                
==5211==    by 0x7B30CB: execute_rtl_store_motion (store-motion.c:1066)         
==5211==    by 0x71349C: execute_one_pass (passes.c:1519)                       
==5211==    by 0x7136C4: execute_pass_list (passes.c:1568)                      
==5211==    by 0x7136D6: execute_pass_list (passes.c:1569)                      
==5211==    by 0x80B8B0: tree_rest_of_compilation (tree-optimize.c:392)         
==5211==    by 0x9836AB: cgraph_expand_function (cgraphunit.c:1160)             
==5211==    by 0x985524: cgraph_optimize (cgraphunit.c:1219)                    
==5211==    by 0x985A5E: cgraph_finalize_compilation_unit (cgraphunit.c:1089)   
==5211==    by 0x4AE2DA: c_write_global_declarations (c-decl.c:9489)            
==5211==    by 0x7B8CAB: toplev_main (toplev.c:1061)                            
==5211==                                                                        
==5211==                                                                        
==5211== 2273 errors in context 2 of 2:                                         
==5211== Conditional jump or move depends on uninitialised value(s)             
==5211==    at 0x7B21FD: store_killed_after (store-motion.c:270)                
==5211==    by 0x7B3221: execute_rtl_store_motion (store-motion.c:1084)         
==5211==    by 0x71349C: execute_one_pass (passes.c:1519)                       
==5211==    by 0x7136C4: execute_pass_list (passes.c:1568)                      
==5211==    by 0x7136D6: execute_pass_list (passes.c:1569)                      
==5211==    by 0x80B8B0: tree_rest_of_compilation (tree-optimize.c:392)         
==5211==    by 0x9836AB: cgraph_expand_function (cgraphunit.c:1160)             
==5211==    by 0x985524: cgraph_optimize (cgraphunit.c:1219)                    
==5211==    by 0x985A5E: cgraph_finalize_compilation_unit (cgraphunit.c:1089)   
==5211==    by 0x4AE2DA: c_write_global_declarations (c-decl.c:9489)            
==5211==    by 0x7B8CAB: toplev_main (toplev.c:1061)                            
==5211==    by 0x6587A25: (below main) (in /lib64/libc-2.10.1.so)               
==5211==  Uninitialised value was created by a heap allocation                  
==5211==    at 0x4C270AC: malloc (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)                          
==5211==    by 0xC90C27: xmalloc (xmalloc.c:147)                                
==5211==    by 0x7B30CB: execute_rtl_store_motion (store-motion.c:1066)         
==5211==    by 0x71349C: execute_one_pass (passes.c:1519)                       
==5211==    by 0x7136C4: execute_pass_list (passes.c:1568)                      
==5211==    by 0x7136D6: execute_pass_list (passes.c:1569)                      
==5211==    by 0x80B8B0: tree_rest_of_compilation (tree-optimize.c:392)         
==5211==    by 0x9836AB: cgraph_expand_function (cgraphunit.c:1160)             
==5211==    by 0x985524: cgraph_optimize (cgraphunit.c:1219)                    
==5211==    by 0x985A5E: cgraph_finalize_compilation_unit (cgraphunit.c:1089)   
==5211==    by 0x4AE2DA: c_write_global_declarations (c-decl.c:9489)            
==5211==    by 0x7B8CAB: toplev_main (toplev.c:1061)


-- 
           Summary: valgrind warns about using uninitialized variable with -
                    fgcse-sm
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: zsojka at seznam dot cz
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41862